Flocking method and machine



Dec. 12, 1967 J. P. DONAHUE E AL 3,357,843

FLOCKING METHOD AND MACHINE Filed Nov.

INVENTORS Jo/m P Dom/mu: SHELDON 7. A/ /ap/r' F F; La

United States Patent 3,357,848 FLOCKING METHOD AND MACHINE John P.Donahue, Hawthorne, and Sheldon T. Wright,

Ridgewood, N.J., assignors to D. & S. Processing Company, Clifton, N.J.,a corporation of Delaware Filed Nov. 5, 1962, Ser. No. 235,411 5 Claims.(Cl. 117-28) The present invention relates to an improved method andmachine for flocking and more particularly to a method and machine forflocking a flexible and stretchable base material. The flocking ofvarious base materials such as woven and unwoven fabrics is Well knownwherein a layer of adhesive is first applied to the base material andthereafter particles or short fibers of fabrics or other materials areapplied to and embedded in the adhesive. The embedded particles, whichare chosen from a variety of different materials depending upon thefinish desired, are known as flock and the application of the particlesto the base material is known as a flocking operation. The resultingproducts have the appearance and feel of suede or velvet.

The method and machine of the present invention are particularly adaptedfor applying a flock coating to a stretchable and elastic base materialsuch as an expanded porous plastic. Known methods of flocking fail toprovide a satisfactorily uniform coating of flock on such materials andin addition, known methods and machines also tend to damage the basematerial by subjecting it to physical manipulations which damage itsform and appearance and by also subjecting the base material to excesstemperatures which cause an undesirable expansion and other injury tothe previously cured plastic base material.

One material which has a wide and growing use for garments such asjackets, coats and vests and other uses where a suede-like appearance isdesirable has a knit or woven mesh fabric coated wtih a relativelythick, soft and stretchable layer of expanded vinyl. The surface of thevinyl is flocked to provide the suede-like appearance. This material issoft to the feel or hand, is easily cut and fabricated, and provideshandsome garments with an excellent appearance and a pleasing drape. Thematerials may be waterproofed and have the long wearing qualities ofsuperior suede leather.

Accordingly, an object of the present invention is to provide animproved method and machine for flocking.

Another object of the present invention is to provide an improved methodand machine for flocking particularly adapted for forming a uniformlyflocked coating on resilient or stretchable material.

Another object of the present invention is to provide a method andmachine for flocking a base material which includes a stretchableplastic layer.

Another object of the present invention is to provide an improved methodand machine for manufacturing a flocked and waterproofed suede-likematerial.

Other and further objects of the invention will be obvious upon anunderstanding of the illustrative embodiment about to be described, orwill be indicated in the appended claims, and various advantages notreferred to herein will occur to one skilled in the art upon employmentof the invention in practice.

A preferred embodiment of the inventon has been chosen for purposes ofillustration and description and is shown in the accompanying drawings,forming a part of the specification, wherein:

FIG. 1 is a diagrammatic side elevational view illustrating a preferredembodiment of the method and machine of the present invention;

FIG. 2 is an enlarged fragmentary perspective view illustrating theadhesive applying and the flocking sections;

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FIG. 3 is an enlarged perspective view partially cutaway showing anexpanded vinyl base material; and

FIG. 4 is a sectional view of the flocked material taken along line 4-4of FIG. 3.

FIG. 1 illustrates a preferred embodiment of the machine 1 for applyinga flocked coating to a soft stretchable material such as the expandedvinyl material illustrated in FIGS. 3 and 4.

FIGS. 3 and 4 illustrate an expanded vinyl base material 2 which istypical of the materials which may be advantageously flocked in themachine and by the method of this invention. This expanded vinyl basematerial preferably has a flexible stretchable cloth base 3 formed ofknitted or woven fabric which is coated with a layer 4 of soft plastic.This plastic coating is often porous or what is known as expanded andalso may be relatively thick, soft, and stretchable. It is formed byincluding suitable blowing agents in a plastic such as a plastisol whichare activated by the application of heat during the plastic curingoperation. Chemically activated blowing agents are also used. Expandedlayers of this nature remain soft and flexible during normal use at roomtemper-atures and higher temperatures, however, such materials aredamaged by the elevated curing and drying temperatures normally used inknown flocking processes.

In addition, the soft stretchable nature of this layer which providesthe desired end use characteristics exposes it to physical damage whenit is handled by the normal flocking devices wherein the base materialis supported on roller systems, is passed between the rollers and iscoated with adhesive or other substances using doctor blades or pressurerollers.

The method and machine of the present invention apply a flocked outercoating 5 to the expanded vinyl or other soft stretchable layer 4 whichprovides the finished product with the feel and appearance and othercharacteristics of suede or other leathers. As illustrated in FIG. 1, aroll 6 of the base material 2 such as the above expanded vinyl base ofFIGS. 3 and 4 is first fed through an adhesive applying device 7 on aconveyor 8 adapted to move and support the material 2 withoutstretching.

squeezing, scraping or otherwise damaging the resilient plastic layer 4.A uniform layer of adhesive is applied to the upper surface of the vinylby one or more nozzles or sprays '9. The spray velocity and pattern areadjusted for the desired adhesive thickness and pattern for the speed atwhich the base material 2 is passed through the adhesive applying device7.

The use of a spray to apply the adhesive has been found to provideunexpectedly excellent results in flocking the above describedstretchable, soft material. This method eliminates the possibility ofdamage to the base 2 by conventional adhesive applicators using doctorblades or leveling rollers while at the same time giving excellentcontrol of adhesive thickness and distribution. Sprays also provide forready adjustment for changes in the desired adhesive depth and also forchanges in the particular adhesive used and a uniformly thick layer isobtained even though there are imperfections on the surface of theunderlying layer 4. Additionally, the enclosed supply system of theadhesive spray eliminates the possible contamination which may occurwith the open-type roller and doctor blade applicators of presently usedmachines.

One adhesive which has proved particularly effective is a water baseemulsion of a vinyl-type resin.

While a reverse roll coater may be used in some instances where theuniformity of the flock coating and the control of the depth of theadhesive are not critical, such an adhesive applicator does not providethe excellent results obtained with the use of the above described spraysystem.

Immediately after the coating of adhesive is applied, the base material2 is passed onto a second conveyor 11 of a flocking device 12. Hereagain, the base material 2 is carried through the flocking device 12 onthe upper run of the conveyor 11 with the base material supported andcarried forward by the conveyor 11 so that no stretching, squeezing orother forces or means are required in moving the base material 2 beneaththe flock applicators. Conveyors 8 and 11 as well as all other conveyorsin the machine move at the same speed.

In the embodiment illustrated, a uniform coating of flock is appliedusing one or more flock applicators 13.

The flocking device 12 is preferably arranged so that the flockingpattern and the flock density may be adjusted and controlled without theuse of any members which engage or which result in pressure upon thesurface of the base material 2. In the preferred embodiment illustrated,control of flock distribution and density is obtained by having theposition of the flock applicators 13 above the base material 2adjustable and by also having the flow rate of the flock from theapplicators 13 adjustable. One particularly suitable embodiment of sucha flocking device is illustrated wherein the flock 14 is applied fromrotating perforated drums 15. The flock 14 is fed into the drums and isdistributed uniformly along the length of the drums 15. The adjustablespeed of the drive motors 16 controls the density of the flock flowwhich is generally proportional to the speed of the motors 16. Thepattern of flock fall is controlled by having the height as well as theposition of the support frame 17 for the distributors 13 adjustable.

The flock particles 14 are continuously fed to the interior of thehollow rotating drums and they are thereafter firmly embedded in theadhesive coating 10 by the combined force of gravity and the vibratoryaction of the base material 2 imparted to it by the rotating beater bars18 positioned beneath and in contact with the flexible conveyor 11. Byproviding two or more generally similar flock applicators 13, a highdegree of uniformity is obtained in the flock coating 5. Electrostaticplanting of the fibers may also be employed by passing the material 2between spaced electrodes 19 and 20 which are charged by an alternatinghigh voltage 21.

The flocked material is next passed through a curing furnace 22 where itis subjected to a heated atmosphere held below the curing temperaturepreviously used in curing the plastic or vinyl layer 4 of the basematerial. For a typical expanded vinyl plastic, the temperature of thecuring furnace is kept below about 270 F.

The improved results are obtained by using a curing atmosphere ofuniform and closely controlled temperature which contacts a relativelylarge area of the flocked surface. This result is obtained in thepreferred embodiment as illustrated by using thermostatically controlledhot air heaters 23 in combination with air directing louvers 24 whichprovide for a uniform distribution of the hot air over the entiresurface of the material contained within the curing furnace 22.

Where the adhesive used is a water base emulsion type, the water ispreferably first evaporated at lower temperatures in the neighborhood of200 F. and thereafter the cloth is passed into a second atmosphere wherethe temperature is raised to the curing temperature which is, as notedabove, held a few degrees below the particular plastic curingtemperature for the resilient stretchable layer 4. As illustrated inFIG. 1, two such zones of differing temperatures and having a uniformtemperature throughout each zone are provided by using separatethermostatically controlled heaters 23 and by providing a dividinglouver 24 in addition to the air directing louvers 24 within theindividual areas.

In handling a relatively long length of stretchable, flexible basematerial, it has been found that there is a tendency for longitudinalcreases or pinches to form in the upper surface of the base materialsuch as when the base material passes through the curing furnace 22.These wrinkles and scars mark the flocked surface and are highlyobjectionable for this reason. The wrinkles, scars, and marks tend to bepermanently formed into the flocked surface during the curing orhardening step in the curing furnace 22. Applicants have found that theflocking of stretchable and relatively thick resilient material isfacilitated and the tendency of wrinkles or pinches to form iseliminated by providing an upwardly facing convex curved surface beneaththe conveyors which carry the base material and particularly the portionof the path through the curing furnace 22. This curvature isconveniently provided by a curved platen 26 as illustrated in FIG. 1.The improved results are obtained by a slight upward curvature which hasbeen found to eliminate wrinkling and pinching without resulting in anysignificant stretching or deformation of the plastic layer or theflocked surface. Relatively slight curvatures provide an unexpectedlyetficient wrinkle preventing action on the flocked material. The exactshape and amount of curvature are not critical. Ina furnace about 10feet long, the uppermost portion of the curved platen surface may beonly a few inches above the level of the platen ends.

The flocked material is now cooled by passing it over cooling rollers27. The material is next preferably passed through a cleaning unit 28where the flocked surface is vacuum cleaned and brushed to remove anyexcess flock not adhered to the base material 2.

In order to increase the utility of the material, particularly where itis to be used for outer garments or other products which must be madereasonably waterproof, the cleaned and flocked material is now given acoating of one of the conventional water repellents used for fabrics.Waterproofing this flocked material has presented special problems andapplicants have found a particularly effective step to insure anadequate absorption of the Waterproofing liquid into the flock while atthe same time preventing the over absorption and spotting which occurswhere the waterproofing liquid accumulates or puddles as is the casewith the present waterproofing operations. This is particularlyimportant in the manufacture of the vinyl coated base material describedherein as the vinyl coating itself is non-absorbent so that any excesswaterproofing solution cannot be absorbed in the material base and thusremains at and tends to stiflien, mark and otherwise detract from theappearance and feel of the flocked surface. Applicants preferredwaterproofing applicator provides a nozzle or spray 30 which is directedagainst the flocked material on an inverted run of the material so thatthe excess solution not readily absorbed by the flocked fibers flows ordrips from the coated material. While the material is shown at 29running on a generally level path durmg this waterproofing operation, itis clear that the base material may be run at an angle to the horizontalduring the operation as long as the flocked surface is facing generallydownwardly so that the excess solution may flow or grip from it and doesnot accumulate on the flocked surace.

The flocked material is now fed into a suitable drying oven 32 for thedrying of the waterproofing solution. Where the waterproofing liquidincludes a resin such as a vmyl plastic, this drying is carried out atan increased temperature governed by the curing temperature of thepartlcular plastic being used. As in the curing furnace 22,thetemperature in the final drying enclosure 33 is held below the curingtemperature of the plastic layer 4 to prevent. any damage to this layerfrom excess heat.

It will be seen that an improved flocking machine and method have beenprovided for stretchable, flexible material and particularly formaterial such as expanded vinyl or other cellular plastic materials.

The method and apparatus handle such material so that max1mum flockingspeed and quality are obtained Without subjecting the material to anydamage such as creases or scars or other marks caused by the physicalhandling or the temperatures used in the drying and curing steps and sothat streaks occurring from the accumulation of dirt behind doctorblades are eliminated. A method and apparatus is disclosed which permitsthe manufacture of greatly improved suede-like or similar flockedproducts having a degree of stretchability and flexibility notheretofore obtained in such flocked material. The method and apparatusof the present invention are also particularly Well adapted for highspeed operation with a minimum amount of supervision so that plants nowusing conventional flocking operations may be converted to the methoddisclosed herein.

The improved method and machine reduces adhesive consumption by reducingpenetration from adhesive applicator pressure and the coating thicknessis made independent of surface imperfections of the undercoat or vinyllayer. Improved product feel or softness also results from the reducedand controlled adhesive layer thickness. The improved Water repellentapplication combines with the improved handling and flocking to furtherprevent spots or marks.

As various changes may be made in the form, construction and arrangementof the parts herein without departing from the spirit and scope of theinvention and Without sacrificing any of its advantages, it is to beundersood that all matter herein is to be interpreted as illustrativeand not in a limiting sense.

Having thus described our invention, we claim:

1. An apparatus for flocking a web of material of soft, stretchablefabric coated with a flexible layer of expanded vinyl comprising thecombination of a supply of indeterminate length of said fabric material,an adhesive sprayer for applying an adhesive coating of uniformthickness and a predetermined pattern onto the vinyl surface of saidfabric material, means for directing an evenly distributed flow of flockdownwardly onto the adhesive coating, an adhesive curing oven, a firstconveyor means having a flat upper surface for carrying said fabricmaterial in an unstressed condition with the vinyl layer uppermostthrough said sprayer and the flocking means whereby a uniform coating offlock is applied thereto, and a second conveyor means having an upwardlyfacing convexly curved surface for thereafter carrying the flockedfabric material through said oven over said curved surface with saidvinyl layer and said Web of material in a wrinkle free condition forretaining said uniformity during the adhesive curing.

2. An apparatus as claimed in claim 1 including a spray means positionedfor applying a liquid water repellent to the flocked surface and meansfor supporting the fabric material in an inverted position for theapplication of the water repellent.

3. The method of flocking a web of material of indeterminate length ofsoft, stretchable fabric coated with a stretchable layer of expandedvinyl comprising the steps of feeding a supply of said fabric material,spraying an adhesive coating of uniform thickness and a predeterminedpattern onto the vinyl surface of said fabric material, planting flockon the adhesive, heating the flocked adhesive, transporting the fabricmaterial on a conveyor means in an unstressed condition with the vinylsurface uppermost during said adhesive applying and flock plantingwhereby a uniform coating of flock is applied and thereaftertransporting the fabric material over an upwardly facing convexly curvedpath while heating said flocked fabric material with the vinyl in anunwrinkled condition for retaining said flock uniformity during thedrying of the adhesive.

4. The method of flocking as claimed in claim 3 wherein the fabricmaterial is heated at about 270 F.

5. The method of flocking as claimed in claim 3 including after theheating step the spraying of a liquid water repellent on the flockedsurface while supporting the material in an inverted position wherebyexcess repellent drops from the flocked surface.

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OTHER REFERENCES Organic Finishing, March 1953, pp. 19-24.

WILLIAM D. MARTIN, Primary Examiner. P. F. ATTAGUILE, Examiner.

1. AN APPARATUS FOR FLOCKING A WEB OF MATERIAL OF SOFT, STRETCHABLEFABRIC COATED WITH A FLEXIBLE LAYER OF EXPANDED VINYL COMPRISING THECOMBINATION OF A SUPPLY OF INDETERMINATE LENGTH OF SAID FABRIC MATERIAL,AN ADHESIVE SPRAYER FOR APPLYING AN ADHESIVE COATING OF UNIFORMTHICKNESS AND A PREDETERMINED PATTERN ONTO THE VINYL SURFACE OF SAIDFABRIC MATERIAL, MEANS FOR DIRECTING AN EVENLY DISTRIBUTED FLOW OF FLOCKDOWNWARDLY ONTO THE ADHESIVE COATING, AN ADHESIVE CURING OVEN, A FIRSTCONVEYOR MEANS HAVING A FLAT UPPER SURFACE FOR CARRYING SAID FABRICMATERIAL IN AN UNSTRESSED CONDITION WITH THE VINYL LAYER UPPERMOSTTHROUGH SAID SPRAYER AND THE FLOCKING MEANS WHEREBY A UNIFORM COATING OFFLOCK IS APPIED THERETO, AND A SECOND CONVEYOR MEANS HAVING AN UPWARDLYFACING CONVEXLY CURVED SURFACE FOR THEREAFTER CARRYING THE FLOCKEDFABRIC MATERIAL THROUGH SAID OVEN OVER SAID CURVED SURFACE WITH SAIDVINYL LAYER AND SAID WEB OF MAERIAL IN A WRINKLE FREE CONDITION FORRETAINING SAID UNIFORMITY DURING THE ADHESIVE CURING.
 3. THE METHOD OFFLOCKING A WEB OF MATERIAL OF INDETERMINATE LENGTH OF SOFT, STRETCHABLEFABRIC COATED WITH A STRETCHABLE LAYER OF EXPANDED VINYL COMPRISING THESTEPS OF FEEDING A SUPPLY OF SAID FABRC MATERIAL, SPRAYING AN ADHESIVECOATING OF UNIFORM THICKNESS AND A PREDETERMINED PATTERN ONTO THE VINYLSURFACE OF SAID FABRIC MATERIAL, PLANTING FLOCK ON THE ADHESIVE, HEATINGTHE FLOCKED ADHESIVE, TRANSPORTING THE FABRIC MATERIAL ON A CONVEYORMEANS IN AN UNSTRESSED CONDITION WITH THE VINYL SURFACE UPPERMOST DURINGSAID ADHESIVE APPLYING AND FLOCK PLANTING WHEREBY A UNIFORM COATING OFFLOCK IS APPLIED AND THEREAFTER TRANSPORTING THE FABRIC MATERIAL OVER ANUPWARDLY FACING CONVEXLY CURVED PATH WHILE HEATING SAID FLOCKED FABRICMATERIAL WITH THE VINYL IN AN UNWRINKLED CONDITION FOR RETAINING SAIDFLOCK UNIFORMITY DURING THE DRYING OF THE ADHESIVE.